A chemical amplification type resist including an alkali soluble resin, an acid generator, and a solubility controlling agent having an acid unstable group is conventionally known as a resist composition used for production of a semiconductor element and so forth. In this type of composition, acid is generated from the acid forming agent when irradiated by ultraviolet rays, electron beam, or X-ray, and the acid thus generated makes chain reaction with the acid unstable groups to change the solubility of the alkali soluble resin so as to form a pattern. As the alkali soluble resin, a novolak resin, a phenol resin, an acryl resin, or copolymers thereof may be used, and there are cases in which an alkali soluble resin also serves as a solubility controlling agent having an acid unstable group, or a resin having an acid unstable group reacts with an acid to become alkali soluble.
However, since the difference in solubility in exposed parts and unexposed parts is generated by the presence or absence of acid unstable groups in a conventional chemical amplification type resist, it is considered that there is a limitation of some degree in performing a fine process.
An object of the present invention includes to provide a high sensitivity and high resolution resist composition which may be used for forming fine patterns by increasing the difference in solubility between exposed parts and unexposed parts.